Pneumatic pumping apparatus



13, 1932. R, CHENAULT l 1,890,720

PNEUMATIC PUMPING APPARATUS Filed Jan. 14, 1952 2 Sheets-Sheet 1 Dec.13, 1932. l R, L, CHENAULT 1,890,720

PNEUMATIC PUMPING APPARATUS Filed Jan. 14, 1932 2 Sheets-Sheet 2 oy L.enau ZZ;

abtoftmq Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE ROY" L.CHENAULT, F PITTSBURGH, PENNSYLVANIAfASSIGNOR T0 .GULF PRODUCTIONCOMPANY, 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION 0F TEXAS rnnna'rlcrUMPING APPARATUS Application led January 14, 1932. Serial No. 586,684.

ThisA invention relates to a pneumatic l pumping apparatus for raisingliquids from deep wells in stages-'and discharging such liquids in acontinuous succession o slugs 4under-a back pressure maintained on theflow line of the apparatus. More particularly, the invention isconcerned withthe pumping of oil "from oil Wells by the use of Aconcentric stringsof tubing. which extend into the wll, one of whichstrings is recprocable to actuate a piston type valve for adotherposition, the liquid .being ejected from the pump in slugs, the velocityof which is retarded by maintaining the pump discharge under a backpressure; all as will be described more fully hereinafter, and asclaimed. v

It is an object of this invention to vprovide a pumping apparatus forraising liquids from deep wells in stages by the admission of a pumpingHuid to the apparatus successively at dierentlevels.

ratus to decrease the emulsiiication of pumped liquids and to eii'ect asaving of energy by maintaining a back pressure on the flow line whichresultsl in a smaller increase in velocity of the pumped liquids as theyapproachl the top of the well and there-` by reduces their turbulenceatthe outlet.

Other and further objects will be apparent from the followingdescription and draw.- ings, in which Figure 1 is a View, partly invertical section, showing the pump and apparatus with which it isassociated in use;

Figure 2 is anenlarged detail view of the upper part of the pumpmechanism with the Valve in one position for pumping;

Figure 3 is a similar enlarged detail'view of the upper part of the pumpmechanism with the valve in the other position :for

pumping Another object is theprovision of appa-- Figure 4 is ahorizontal sectional view, taken along the line 4 4 of Figure 2;

Figure 5 is a horizontal sectional view, taken along the line 5-5 ofFigure 2;

Figure 6 is an enlarged detail view of the lower end of the pump, invertical section, showing a modified form of foot valve in one positionof pumping;

Figure 7 1s a vlew s'. 'lar to Figure 6, but

. showing the 'modified form of foot valve in the other position ofpumping.

Referring` more particularly drawings: l

to the v' A casing 10 extends into the bore of a. well and encloses twoconcentric strings of tubing 11 and 12, the outer of which is composedof a displacement chamber 13 and a valve cylinder 14 in axial alignmentand connected to the tubing 11 by a nipple 15. This string is run firstmto the Well to a oint where the displacement chamber is su merged inthe liquid which is to be pumped.

The inner string of tubing 12 is next lowered into the well within thestring 11.` The tubing 12 comprises an eduction pipe 16 which isattached to a piston valve 17, the valve, in turn, being connected tothe tubing 12. by a nipple 18 and threaded sleeve 19.

The foot valve assembly 20 may also be lowered Vinto position in theseat 21 which forms the-end of the displacement chamber,

by means of the rod 22 which is attached to the valve cage and whichextends up into the eductor pipe 16 to be slidably received therein butprevented from removal bythe head 23 which cannot pass the projection 24in the eductor pipe. This arrangement permits all\ working parts' to beremoyed for repairs or replacement by pulling the single inner string oftubing.

The foot valve assembly 20which is shown in Figure 1 and which includesa ball check valve may be replaced by a foot valve ofthe type shown inFigures 6 and 7 wherein a pipe 25 is connected to theeduct'or pipe 16 bya Esleeve 26 and is closed at itsend by a plug 27 which is tapered topermit installation and removal of the pipe 25 with the inner stringoftubing.

seat member 21 and is slotted at 28 so that when the inner tube stringis lowered to the positionv shown in Figure 6 communication isestablished between the displacement chamber and the interior of thewell, whereas when the string is raised to the position shown in Figure7, while the displacement chamber is being emptied, communicationbetween the displacement,chamber and well is cut olf. Y f

The piston valve cylinder. has inner and outer walls deinin separateannular spaces 29 and 30 above an below the connecting web 31, and thespaces, respectively, communicate with horizontal ports 32 and 33 whichopen into the interior of the cylinder. Exhaust ports 34 (Figures 2, 3and 5) extend horizontally from the interior of the valve cylinder tothe space between the outer tube string and the well casing. A radialseries yof' such exhaust ports is provided as is shown in Fig'I ure 5.

The piston valve 17 is equipped with piston rin or other suitablepacking for making a tlght seal between the various valve ports and thetwo ends of the valve, these rings or packings defining annular spaces35 and 36 for connecting the various valve ports. Ports 37 connect theannular groove or space 36 with the hollow interior of the piston.

A check valve 38 is provided and may be v located either in the eductorpipe 16, as shown, or in the piston'valve at any point be- .low the orts32.

A stu g box 39 is provided at the top of the well which forms a tightseal between the two strings of tubing and allows the inner string to beraised and lowered suiiciently to operate the piston valve 17. Y

Y Any convenient lifting mechanism may be employed for raising andlowering the tube string 12. The preferred'mechanism, however, is shownin Figure 1 and it comprises a pneumatic power cylinder 40, controlledby an automatic timing valve 41 which admits compressed air or gas tothe cylinder for raising the tubing 12, and, alternately exhausts themotive fluid from the cylinder to the atmosphere allowing the tubing tolower by gravity, The time interval for raising and lowering the tubingis controlled by regulation of the automatic valve. A mechanical orhydraulically operated lifting mechanism may be used in place of thepneumatic apparatus shown, if desired.y

In the illustrated system a compressor 42 receives gas or compressed airfrom a separating chamber '43 which is maintained unl der pressure, andforces such fluid through pipe44, past valve 45, into the space betweentube strings 11 and 12 within the pump. A branch conduit 46 extendsbetween the pipe 44 and the cylinder 40 and has'therein valves Aflexible connection 51 is provided in the ,l

outlet tovpermit reciprocation of the inner tube string. Y

In assembling the pump the displacement chamber 13 is lowered on theouter string of tubing 1.1 until it is in the well liquid. It will fillwith liquid to the level of liquid in the well. The inner string oftubing 12 is then lowered until the piston valve 17 is in its workinposition in the valve cylinder 14. This position may be determined bynoting the distance between the lower end of the eductor pipe 16 and thecage of the foot valve 20, when the piston valve is in its properworking position, before the device is installed in the well. The innerstring is lowered until the lower end of the eductor pipe rests onladmit compressed air or gas to the hoist the inner string of tubing israised suiciently to lift the piston valve 17 to the position shown v inFigure 3.I Inthis position the -annular space between the two strings oftubin communicates with the displacement cham r 13 by means of thevertical passages'29, 30, the horizontal ports 32, 33 in the cylinderwall, and the annularl space 35 around the piston valve.

Compressed air or gas is admitted to the space between the tube stringsby opening the valve 45, and thenlowsdown around the piston valve to thedisplacement chamber where it exerts a downward force on the liquidtrapped therein, seating the valve 20 and forcing the oil up through theeductor pipe 16 and past the check valve 38 toward the surface throughthe inner string of tubin After suilicient time has elapsed or thedisplacement chamber to be emptied of its charge of oil the inner stringof tubing is lowered by shifting the timing valve to the exhaustposition shown (in Figure 1, thusvrelieving pressure below the powerpiston in chamber 40, through the medium of which the inner tube stringis reciprocated. The piston valve 17 is, thus, returned to its lowerposition as shown in Figures 1 and 2 and the pressure in thedisplacement chamber vis relieved by exhausting the gas to the wellcasing 10 through the vertical passage 30, the ports 33, the annularspace 35 aroundthe piston valve, and the exhaust ports 34 (Figurels1 2and 5) vleading through the cylinder Wa a 'i v When Athe piston valve islowered, the annular space 36 between it and the cylinder wall isopposite the ports 32 so that compressed a1r or gas is admitted to theinterior of the piston valve through the ports 37 and continues to liftthe oil which has been raised previously to a level above the checkvalve 38, at the same time the displacement chamber' is being exhaustedand refilled with a new char e of wellfluid.

A er suiiicient time has elapsed for the gas pressure to exhaust fromthe displacement chamber and a new charge of oil to flow in through thecheck valve 20, Figure 1, or the slot 28 in pipe 25 as shown in Figure6, the piston .valve is again raised by raising the inner string oftubing whereby the check valve 20 is seated against return flow ofliquid from thefdisplacement chamber, or, if the modified form of valveis used, the slotted pipe 25 will be raised to the position. shown inFigure 7 to cut oif communication between the well and the displacementchamber to prevent back flow of.y liquid. Another charge' of oil is thenforced up the eductor ipe and into the inner tubing, and the cyc e isrepeated. Thus, afnumber of separate slugs of oil, separated bycolumnsof compressed air or gas, may be put into the inner string or flow line,andthe admission of a new charge does not interfere in any way with theprogress of the slugs of oil and gas traveling up the How line tothe'well outlet.

The ability to exhaust the'displacementA chamber and pick up a newcharge of oil before preceding charges reach the surface isl animportant feature of this apparatus, especially where uid levels are lowand the well depth is greatfith low'fluid levels a short displacementchamber must be used, and the volume of fluid picked up per stroke is.necessarily small in wells of small diameter. If this relativelv smallslug must be brought to the surface from a great depth before thedisplacement chamber can be ex-y hausted and refilled` with oil, therateof ypro duction is necessarily low and the gas or Aair consumption ishigh. v In the use of the present inventio'n, however, as many slugs asdesired may be put into the flow line by regulating the frequency ofoperation of the piston valve, by adjusting the timing valve, or byvarying the air or gas pressure to change the velocity of' flow up thedischarge line. As the slugs of oil and gas reach the surface they flowthrough the discharge pipe 50 and flexible connection 51 to theseparator from which the oil is withdrawn through an out.

let at a l low point while the gas is taken off Y from a high point inthe separator and is led back to the compressor ,for re-cycling. p

` Gas exhausted from the displacement chamber to the space withinthewell casing may be withdrawn by a vacuum gas gathering line mergence.

-in the case of the ordinary orlit may be conducted back to thecompressor in et.

It is seen that this method of producin oil may be utilized in wellshaving low flui levels where'it is impossible to use the regular gaslift system because of insuiiicient sub- No back pressure is placed onthe producin horizon when this apparatus is used as t e gas pressure isconfined within the pumping unit and not the well casing as gas lift.

There are no ,pick-up losses such as occur in the regular gas lift as aresult of gas slipping through the oil, especially in cases wherethe'submergence is low. With .this apparatus the flow of oil isaccelerated by the pressure of air or4 gas acting downward on a fluidpiston, and there is no' possibility of slippage during the time acharge of oil is being accelerated and started up the flow string. Thearrangement of surface equipment shown in Figure 1 is especialldesirable as it permits a back pressure to. held on the flow lineand thegas separator. Operating with back pressure has advantages bo'th fromthe standpoint of energy. required, andthe size and cost of equipment.The 'size of the compressor and separator equipment necessary is reducedbyoperating with back pressure, because when Working between the samepressure difference between inlet and exhaust, the compression ratio isless when exhausting to a pressure above atmospheric than whenexhausting to atmosphere. This effect is better illustrated by thefollowingA separator, to operate the pum Then takin 1?# g atmosphericpressure as 14 /sq. in., the

compression ratio when exhausting to at-mosphere is gage pressure andsupplying air or gas to the pumpk at 250:94?. gage pressure, thecompression-ratio is `Thus 'it is seen that the compressor displacementnecessary to supply the volume of gas or air at the required pressure istimes as great when exhausting 'to atmospheric'A pressure as whenexhausting to a gage pressure of 50# and supplying gas back to thecompressor intake at this pressure.

This effect is greater the higher the back pressure used, and theoptimum conditions will be determined by the limitations of theequipment used. Besides the reduction in compressor'capacity, a furthersaving in compressor costs will result from the fact that a single-stagecompressor can be used ,mosphere in many cases when pumping with backpres- A of a. given mass of gas a given amount decreases as the pressureincreases; Referringl again to the example cited above, when compressingair from atmospheric to 200# gage pressure, the theoretical energyrequired per cubic foot of free 'air for isothermal compression is 5,676foot pounds, while the en ergyrequired to compress 1 cubic foot of freeair isothermally from a pressure of 5 0# K gage to 250# gage is only2,982 foot pounds.

However, a greater mass of air is required in the system at the higherpressurein the ratio ofv the absolute pressures of the two ex amples, or

Then the net saving in energy required when operating between and 250#gage v pressure is 5,676*2,982 1.23=2,000 ft. lbs.

per unit volume the equivalent of that occu pied by'a cubic foot of freeair when compressed to a pressure of 214.7# abs., or

m .0685 C11.' p'

at the working pressure in either case. ThisA represents a saving ofabout 35.5% in energy when operating against a back pressure of 50#gage. The saving when compressing adiabatically is about the same as forisothermal'compression, although the actual` energy required is greaterboth with backl pressure and when exhausting to atmosphere.

A further advantage of back pressure is thatresulting from the smallerincrease in velocity as the fluid being vpumped approaches the top ofthe well, since the expansion ratio*is much less when pumping againstany considerable back pressure. This acceleration of the well fluid asit approaehes the surface has been a source of considerable trouble inordinary gas ,lift practice. The high velocities resulting fromexpansion of the gas as the pressure diminishes when it progresses upthe How line, greatly increases the turbulence, and trouble fromemulsions in wells which are producing both oil and water. Theresistance to iiow also increases rapidly with the velocity. The

effect of back pressure in diminishing the acceleration toward ,thesurface is readily seeny by referring again to the two examples cited.When the air or gas is exhausted to atmosphere the expansion ratio is14.6. When exhaustingv to a back pressure of 50# gage the expansionratio is 4.1 or less than l, that of the former case. This will resultin a corres onding decrease in acceleration of the well uid as itapproaches the surface, and a more uniform velocity of flow throughoutthe length of the flow line.

It should be pointed out that the advantages resulting from theutilization of back pressure with this device are obtained withoutputting any undesirable back pressure on the. producing formation. Thepressure required to operatethe device is confined entirely within thetwo strings of tubing and the displacement chamber. If back pressure onthe producing sand is desired for any reason, it may be held in thecasing without interfering with the operation of the device.

In cases where extremely low fluid levels are encountered, making itimpossible to collect the'V displacement chamber full of fluid bygravity, a packer may be set at any point below the exhaust ports 34making a tight sealsbetween the displacement chamber, or Diston valveand well casing. If the casing is then connected to a vacuum gasgathering line, the displacement chamber may be eX- hausted to apressure several pounds below atmospheric and oil may be made to rise inthe displacement chamber to a point several feet above the Huid level invthe well, re sulting in an increase in speed and eiiiciency ofpumping.r

I claim: v

1. Pneumatic pumping apparatus for deep wells which comprises adisplacement chamber adapted to extend into the liquid of a well, aneduction pipe extending into said displacement chamber, a source ofpneumatic pressure, valve means positioned on said eduction pipe foralternately connecting said source of pneumatic pressure with thedisplacement chamber and then with the eduction pipe, whereby when thevalve means is in one position the pressure o'f pneumatic fluid isdirected into the displacement chamber to `force liquid therefrom intothe eduction pipe and upon reversal of the said valve means the pressureof the pneumatic fluid is directed int-o the eduction pipe to lift theliquid1 in the eduction pipe to the surface of the We 2. Pneumaticpumping apparatus for deep Wells which comprises a displacement chamberhaving valved communication with the interior of a well below thesurface of liquid therein, an eduction pipe extending into saiddisplacement chamber, a source of pneumatic pressure, reciprocatingvalve means positioned on said eduction pipe for alternately admittingpneumatic fiuid under pressure first to the displacement chamber andthen to the eduction pipe, a valve in said eduction pipe below the pointof admission of pneumatic fluid to prevent return of liquid forced fromthe displacement chamber, whereby in one position of the reciprocatingvalve means the force of pneumatic fluid is directed into thedisplacement chamber to force liquid ltherefrom into the eduction pipeand past the said valve therein and in another position of thereciprocating valve the force of the pneumatic fluid is directed intothe eduction pipe to lift the liquid in the eduction pipe to the outletof the well in slugs, and means for simultaneously relieving thedisplacement chamber of pneumatic pressure to permit its refilling byliquid from the well preparatory to another cycle of operation.

In combination with a source of fluid under pressure, a pump comprisinga displacement chamber immersed'in the liquid to be pumped, a valve foradmitting well liquid into said chamber but preventing its returnl flowinto't-he well, a valved eduction pipe ex-- tending to a low point insaid displacement chamber, a reciprocating piston type valve positionedon said eduction pipe coaxial therewith, said valve serving to connect asource of fluid under pressure alternately with the displacement chamberand the eduction pipe above the valve therein. whereby said fluidunder-pressure is first admitted to the displacement chamber to forceliquid therefrom up into the eduction pipe and secondly uponreversal ofsaid piston type valve said fluid under pressure is admitted to saideduction pipe to lift the liquid to the surface of the well insuccessive slugs said valve also simultaneously relieving thedisplacement chamber of pneumatic pressure, whereby the chamber isrefilled by liquid from the well preparatory to another cycle ofoperation.

4. A deep well pump comprsing a tube string divided int-o upper andlower ported chambers, a dispacement chamber on the lower end of saidtube string. an eduction pipe extending through said tube string andterminating in said displacement chamber, a piston type valve coaxialwithysaid eduction pipe and reciprocable to alternately cover anduncover the ports in said upper and lower chambers, said eduction pipe,further, being the displacement chamber, thereby to force well liquidinto the eduction pipe by downwa rd pressure upon the surface of suchliquid and to substantially empty the displacement chamber, and wherebywhen the piston type valve is reversed, communication of fluid underpressure with the displacement chamber is cut off but is simultaneouslyestablished between the said upper chamber and the eduction pipe throughthe ports therein to further lift the liquid toward the surface of thewell in successive slugs.

5. A deep well pump comprising concentric strings of tubing, the outerof which terminates at its lower end in a displacement chamber, a valvedinlet in said displacement chamber, a pi ston cylinder open at bothends, supsaid cylinder, and an eduction pipe extending y into saiddisplacement chamber, a plurality of enlargedpiston heads forming partof said piston type valve and closely received within said cylinder,ports extending through said piston type valve between certain of thepiston heads, and a check valve in said inner tube string below saidports in the piston type valve` a source of fluid pressure communicatingwith the space between the outer and-inner tube strings, whereby uponreciprocation of the inner tube string compressed fluid will be admittedto the displacement chamber by passing through the ports on either sideof the web element and around the piston type valve, thus exertingdownward pressure on the liquid in the displacement chamber and forcingit up the inner tubestring past the check valve therein, from whichpoint it is lifted by fluid pressure when the position of the pistontype valve is reversed vto admit the pumping fluid through the ports insuch valve, and means for simultaneously venting the displacementchamber to relieve it of pressure for refilling with well liquidpreparatory' to another cycle of operation.

6. Pumping apparatus for wells comprisi and lower chambers, an innerstring of tubing for discharging liquid from the well, a reciprocablevalve carried by said inner string of tubing for -establishing and'interrupting communication between a source of pumping fluid and saidstrings of tubing, respectively, a fluid operated piston forreclprocating said valve and inner tube string, a compressor for forcingpumping fluid into the outer tube string and intermittently into theinner tube string upon actuation of the valve, a separating chamber,piping connecting the inner string of tubing with said chamber toconduct pumpirfglluid and well liquid from the inner string 'of' tubingthereinto, said separating chamber being maintained undersuperatmospheric pressure, andpiping leading from said separatingchamber to said compressor, whereby the compressor and flow line of theapparatus will be maintained under back pressure.

7. A pneumatic pumping system in which no back pressure is placed on theproducing horizon, consisting of two concentric strings of tubing,n astuing box carried by the outer string of tubing to permit the innerstring Vto be raised and lowered without leakage between the two saidconcentric strings, a piston -type valve attached to the inner movablestring of tubing, a cylinder for said valve within the outer string oftubing, a displacement chamber attached to the outer, stationary stringof tubing at its lower end and extending into the well hquid, a checkvalve in the bottom of the displacement chamber for admitting liquidfrom the well, an eduction' pipe extending into the displacement chamberto provide a continuous passage through the piston type valve h fordelivering liquid from the displacement chamber to the inner string oftubing, a check valve in the eduction pipe, means for supplymgcompressed gas to the annular space between the two strings of tubing,and means for admitting compressed gas to the displacement chamber fromthe annulus between the two strings of tubing, and means for exhaustlngcompressed gas from the displacement chamberV by vertical motion of theinner string of tubing.

A .pneumatic pumping apparatus comprismg inner and outer concentricstrings of tubing, a displacement chamber at the lower end of the outerstring of tubing, a flow line of less diameter than the displacementchamber, reciprocating valve means carried by the flow line foradmitting compressed gas intermittently to the displacement chamber toact downwardly on the surface of liquid therein and force it into theflow line, the valve means being reciprocable to interrupt the flow ofpumping fluid to the displacement" chamber, whereby it may be relievedof pressure, an exhaust port from said outer string of `tubing, a wellcasing surrounding the concentric strings of tubing and a packingbetween the well casing and, outer string of tubin below the exhaustport therein to permit t e pressure in the casing to be reduced belowatmospheric for increasing the volume of well liquid collected in thedisplacement chamber which extends above the normal Huid level of thewell.

9. In combination with a source of fluid under pressure, a pumpcomprising a displacement chamber immersed in the liquid to be pumped, astuing box vin the lower end.

of said displacement chamber, a hollow, ported rod extending throughsaid stuiiing box and reciprocable to establish or interruptcommunication between the interior of a well and the interior of saiddisplacement chamber, an eduction pipe extending into said displacementchamber and attached to said hollow rod, a reciprocable piston typevalve coaxial with said eduction pipe to establish communication betweenthe source of fluid under pressure alternately with the displacementchamber when the hollow rod is in position to close the displacementchamber at its lower end, and with the eduction pipe at an intermediatepoint therein, a check valve in said eduction pipe below suchintermediate point, whereby when fluid is admitted to the Vdisplacementchamber to force liquid r therefrom up into the eduction pipe, theliquid is prevented from owing back to the displacement chamber by saidcheck v alve whereupon, when the position of sald plston type valve isreversed, the column of liquid is lifted to the surface of the well insuccessive slugs while, at the same time, the flow of pumping fluid tothe displacement chamber aving been interrupted, such chamber 1srelieved of pneumatic pressure and, the hollow ported tube having beenreciprocated simultaneously with the piston type valve, the displacementchamber is refilled with liquid preparatory to another cycle ofoperation.

10. Pneumatic pumping apparatus for deep wells comprising a well casmg,a pipe positioned in said well casing, a piston valve and an eductionpipe positioned in said first mentioned pipe, said piston valve dividingsaid first mentioned pipe into an upper chamber-for the reception ofcompressed air and a lower chamber adapted'to be submerged in the liquidin the well, the piston valve 'adapted to alternately admit compressedair into said lower chamber and then into said eduction pipe, saidpiston valve exhausting air from said lower chamber into the well casingduring admission of air into the eduction pipe.

11. Pneumatic pumping apparatus for deep wells comprising a pipepositioned 1n said well, a piston valve and an eduction pipe positionedin said first mentioned pipe, said piston valve dividing said firstmentioned I pipe into an upper cnamner for the reception of compresseda'ir and a lower chamber adapted to be submerged in the liquid in thewell, the piston valve adapted to alternately admit compressed air intosaid lower chamber and then into said eduction pipe, said piston Valveexhausting air from said lower chamber into the well during admission ofair into the eduction pipe.

12. Pneumatic pumping apparatus for deep wells comprising a pipepositioned in said well and a combined piston valve and eduction pipepositioned in said first ,mentioned pipe, s aidpiston valve dividingsaid first mentioned pipe into an upper chamber for the reception ofcompressed air and a lower chamber adapted` to be submerged in theliquid in the well, the valve means adapted to alternately admitcompressed air into said lower chamber and then into said educ- 'tionpipe, said valve means exhausting air from said lower chamber into thewell during admissionof air into the eduction pipe.

13. In apparatus for pneumatically pumping liquids from wells, adisplacement chamber and an eduction pipe in communication therewith atits lower end, means for filling said chamber with liquid from the wellto cover the lowerl end of said eduction pipe, means for admittingcompressed air to the said chamber for discharging the liquid from thechamber into the eduction pipe, and means for supplying compressed airto the eduction pipeduring the fillin of the chamber withl oil from thewell to ift the oil in said pipe and discharge it from the Well, the oilentering said eduction pipe during discharge thereof fromsaiddisplacement chamber, continuing to lift the 4oil in said eduction pipeto continuously discharge it from the well after admission of air to theeduction pipe has been discontinued.

14. In apparatus for pneumatically pumping liquids from wells, a wellcasing, a pipe extending into-said well casing and comprising a chamberhaving an upper part and a lower displacement part and an eduction pipesurrounded by said chamber and in communication therewith at its lowerend, means Y for filling said chamber with liquid from 'the well tocover the lower end of said eduction pipe', hollow valve members in saidrst mentioned pipe between the upper and the lower` parts thereof foradmitting compressedfair to the said displacement part and fordischarging the liquid therefrom into the eduction pipe, means forreleasing the pressure in therewith at its lower end, means for llingsaid chamber with liquid from the well to cover the lowenend of'saideduction pipe, means for admitting compressed air to the said chamberfor discharging the liquid from the chamber into the eduction pipe,means for releasing the pressure in the dis lacement chamber to permitentrance thereo of liquid from the well, and means for substantially ingliquids from wells, a well casing, a pipe Y extending into said wellcasing, a valve dividing said pipe into an upper part for the receptionof compressed iuid and a lower chamber extending into the liquid in thewell, and an eduction pipe positioned in said rst mentioned pipe andterminating in said lower chamber, operating means for said valveto'position it to admit compressed fluid into the lower chamber froml asource of compressed 'luid supply to force the liquid in said chamberupwardly in the eduction pipe and means for operating said valve toadmit compressed iiuid into the eduction pipe at a point below the levelof the liquid which has been forced into said pipe by the compressed airof the lower chamber, whereby the liquid in the eduction pipe may belifted to the .top of the well, and means operable by said valve torelease the pressure of the Huid in the lower chamber during theintroduction of the compressed iuid to said eduction pipe.

. 17. Apparatus for pneumatically pump-` ing liquids from deep wellscomprislng a dlsplacement chamberpositioned in the liquid at the bottomof the well, an eduction pipe communicating with said displacementchamber and extending to the top of the well, a valve positioned in thewell adjacent the eduction pipe and displacement chamber said valvebeing connected to a source of Huid pressure and adapted to alternatelyconnect rst, said displacement chamber and then Asaid eduction pipewithcvthe source of compressed luid and means including said eductionpipe for controlling the operation of said valve.

18. Apparatus for pneumatically pump-4 ing liquids from deep wellscomprising a displacement chamber positioned in the liquid at the bottomof the well, an eduction pipe communicating with-said displacementchamber and extending to the top of the well, a valve positioned in thewell, and means extending t the top of the well for controlling theoperation of said valve, said valve being connected to a source of fluidressure and adapted to alternately connect rst said displacement chamberand then saideduction pipe with the source of compressed uid for pumpingthe liquid out of the well.

In testimony whereof, I have hereunto affixed my signature.

ROY L. CHENAULT.

